The present invention generally relates to doctor blade holders and relates in particular to doctor blade holders that may be used with roll surfaces wherein the roll surface is not uniform.
For example, certain types of rolls, such as Yankee rolls used for making tissue paper, may have very large diameters that are not uniform along the longitudinal direction of the roll. Certain such rolls, for example, may have a diameter at the center of the roll that is greater than the diameter(s) at the ends of the roll. This may be by design to facilitate the transfer of an intermediate tissue product onto the roll, but presents difficulties in trying to provide a doctor blade that matches the surface of the roll.
Conventionally, adjustments of the position of a doctor blade along the length of a roll have been achieved by providing adjustment screws at spaced apart locations (e.g., every few inches) along the length of the doctor blade holder that urge the doctor blade closer to the roll surface. Unfortunately, however, such adjustments may compromise other portions of the doctor blade holder, such as locations where the doctor blade holder is attached to a holder mounting plate or doctor back, and may further introduce inconsistencies in the pressure applied by the doctor blade onto the roll surface.
There remains a need therefore, for a doctor blade holder that efficiently and effectively permits small localized adjustments of the position of a doctor blade without the above attendant drawbacks.